Patent US1656956A successfully refreshed from Google Patents.
US1656956A
Expired / Lapsed
US
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Electric vacuum valve tubb
Assignee: AT&T Inc
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Filing: 1921-03-30
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Granted: 1928-01-24
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Expires: 1941-03-30
Abstract
No abstract record available.
Inventors
- 👤 Schroter Fritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:46
CPC Classifications
H; H01; H01J; H01J17/00; H01J17/38; H01J2893/00; H01J2893/0064; H01J2893/0065; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/929
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1931-01-23 | 1931-07-25 | 1932-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1935-01-23 | 1935-07-25 | 1936-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1939-01-23 | 1939-07-25 | 1940-01-24 | $7700.00 | Window Closed / Lapsed |